Inter-integrated circuit (I2C) communication protocol is based on a single-ended bidirectional bus and is intended primarily for attaching low-speed peripherals or devices to a motherboard or similar electronic device where the physical separation between devices is minimal. Single-ended buses are less robust in terms of both transmission speeds and transmission distances compared to differential buses. As a result, connecting an external device such as a printer to an I2C chip is difficult, because of the distance limitations of a single-ended bus.
Differential signal transceivers convert single-ended signals to differential signals, which are suitable for transmission over greater distances. Certain differential signal transceivers require a unidirectional TX input (e.g., from the I2C chip) and supply a unidirectional RX output (e.g., to the I2C chip). However, as explained above, the I2C protocol is based on a bidirectional input/output pin.